Thus Richard, who accepts regulation and was instructed to report on it for the Paris Municipal Council, would not have girls inscribed as professional prostitutes until they are of age and able to realize what they are binding themselves to (E. Richard, La Prostitution à Paris, p. 147). But at that age a large proportion of prostitutes have been practicing their profession for years.
In Germany, where the cure of infected prostitutes under regulation is nearly everywhere compulsory, usually at the cost of the community, it is found that 18 is the average age at which they are affected by syphilis; the average age of prostitutes in brothels is higher than that of those outside, and a much larger proportion have therefore become immune to disease (Blaschko, "Hygiene der Syphilis," in Weyl's Handbuch der Hygiene, Bd. ii, p. 62, 1900).
A. Sherwell, Life in West London, 1897, Ch. V.
Bonger brings together statistics illustrating this point, op. cit., pp. 402-6.